There are many situations in which it is desired to insert a tube or pipe, particularly a flexible tube, into a relatively long and narrow channel or lumen or outer pipe. Such tube can be used to deliver fluids or an instrument to the end of the channel for medical and mechanical uses. At present, methods for such delivery include using guide wires or using tubes which are semi-rigid for ease of insertion. Common medical uses of such tubes include various endoscopic procedures, catheterization, and cleansing of the colon before performing colonoscopy examinations.
One of the most unpleasant and difficult stages of colonoscopy examination is the preparation of the patient prior to the examination. This preparation involves cleansing the patient's bowels and colon. During a colonoscopy procedure itself, patients are sedated so that they do not feel any pain, and sometimes do not even remember the test. However, the preparation is usually performed at home, and it can be quite challenging.
When using ingested laxatives, it can require the consumption of large volumes and/or of distasteful products. The exact laxative menu which is used varies according to the physician's or patient's experience, taste, and preference.
One consequence of this often unpleasant, and occasionally unsuccessful, preparation experience is that there are patients who undergo colonoscopy, the preparations for which are imperfect or suboptimal. Poor preparation impairs the detection of colonic neoplasms, particularly small lesions, but even large tumors can be missed due to solids in the colon under examination.
The main advantage of laxatives, used in the conventional method for colon cleansing, is that they cause cleansing in the normal direction of elimination of solids and liquids in the colon, that is, from the small intestine toward the anus. In this direction, the fecal matter is eliminated from the body, in a way similar to that in normal human bowel movement activity.
Mechanical cleansing methods, such as an enema and hydrotherapy irrigation, introduce fluids from the rectum in the direction of the small intestine, that is, in the direction opposite to the normal flow. These fluids are limited in their ability to reach far up the colon, and typically cleanse only about the lower third of the colon.
A number of prior art devices are known in the art which describe colonic cleansing in order to dislodge and remove fecal material from the patient's colon. These include: U.S. Pat. No. 4,182,332, which shows an insertable rectal catheter with a series of flanges contacting the rectal mucosal tissue. Such flanges would be likely to cause leakage, irritation, and infection of the tissue.
U.S. Pat. No. 4,067,335 provides a fecal matter collecting unit with an insertable funnel with a series of ribs contacting the rectal mucosal tissue. These ribs allow leakage and put too much pressure on the tissue adjacent to each rib, which could cause irritation and infection. U.S. Pat. No. 5,741,239 provides a fecal collection receptacle and tapered neck, a broad-lipped sealing ring with a bottom broad smooth flat sealing rim surface for contacting the rectal mucosal tissue that needs an external device for insertion and takes much space, causing an uncomfortable feeling in the rectal area.
U.S. Pat. No. 5,941,860 provides a fecal collector which comprises an elongated, flaccid pouch having an entrance end; an anchor attached to the pouch entrance end to anchor the entrance end in the lower bowel; and a positioner attached to the pouch in spaced relation to the anchor O-ring, to remain outside the lower bowel and adjacent to the body, for blocking tilting of the anchor in the bowel. This arrangement needs an external device for insertion and takes much space, which causes an uncomfortable feeling in the rectal area.
Lubricants or gels have been used to aid the insertion of devices through the rectum or anal canal area. U.S. Pat. No. 3,881,485 to Davis, Jr. (“Davis”) discloses a device for insertion through the anus into the upper rectum for the purpose of wiping the walls of the rectum clean of feces and stopping and retaining feces in the colon and rectum at a distance from the anus. The invention is a preformed fiber device that is shaped for insertion through the anus into the upper rectum. The device is inserted through the anus and up through the rectum with a coating of non-irritating lubricant applied to the wiper. The lubricant should preferably be an organic, inert, water soluble gel, but other suitable lubricants may be used.
Other prior art patents disclose colon cleaning systems and methods that introduce an enema solution (i.e., preferably with a laxative) into the colon through the anal opening via a suitable tube held in the rectum by an inflated bladder or balloon. The balloon and a tube are introduced into the body of the patient (i.e., via the anus and to the rectum/colon). U.S. Pat. No. 4,403,982 to Clayton, U.S. Pat. No. 4,406,655 to Clayton, and U.S. Pat. No. 4,842,583 to Majlessi provide examples of such devices.
However, these bladder or balloon devices require regulation of the pressure to the bladder or balloon, and they have the problem of the possibility of injury occurring to the patient if the pressure is not regulated properly.
U.S. Pat. No. 5,049,138 to Chevalier et al. (“Chevalier”) discloses a catheter having a tip that dissolves inside the body. The catheter includes a flexible tubular member that has an inner lumen and a rigid solid tip disposed at the end of the inner lumen. The tip (i.e. cone shaped) is formed of a material that is slippery when wet, soluble in bodily fluids and capable of absorbing radiographic fluids that are injected into the inner lumen for identification of the location of X-rays. A narrow passageway is disposed in the tip and is adapted to receive a guide wire for insertion of the catheter into an internal organ. Other devices include those disclosed in U.S. Pat. No. 6,984,226 of Abell et al, U.S. Pat. No. 5,190,519 of Mead et al, U.S. Pat. No. 5,176,630 of Shilling, et al., U.S. Pat. No. 5,405,319 of Abell et al., U.S. Pat. No. 5,019,056 of Lee et al., and U.S. Pat. No. 4,874,363 of Abell. The primary purpose of each of these devices is the delivery of liquid into the colon through the anus of a patient for dislodging fecal material that may be lodged therein and then removing or draining the dislodged material along with the waste liquid from the colon to evacuate the bowels of the patient. Patent Application No. US 2007/0015965 of Cox et al, states that the cleansing of the colon for colonoscopy purposes needs to enter physically deep into the colon, however the method described uses a semi rigid tube, which is the same as performing an actual colonoscopy in parallel with or before the regular colonoscopy.
U.S. Pat. No. 6,988,988 discloses an apparatus for endoscopic inspection including an anchor unit for anchoring outside a body tract, a flexible sleeve coupled to the anchor and having a distal end fixed to an internal unit adapted to be propelled through the gastrointestinal tract. The sleeve is held initially in a compact state (accordion folds) in the internal unit and is arranged to feed out from the internal unit as the internal unit is advanced into the gastrointestinal tract. However, U.S. Pat. No. 6,988,988 provides an “internal unit” (or a probe) with a transparent optical window or lens and electro-optical package.
It was found by the inventors of the present invention that such an “internal unit” would have difficulties while navigating within the colon and most probably would be stuck and jammed within the colon (due to friction forces between the colon and the unit) instead of navigating throughout the same.
According to U.S. Pat. No. 6,988,988, in order to ease navigation of the “internal unit” through the colon, the same is provided with a steering unit. Such steering unit enlarges the dimensions of the “internal unit” and further increases the difficulties in navigation thought the colon.
Thus, there still remains a long felt need for an endoscopic apparatus which will enable easy navigation while minimizing the friction forces.
Furthermore, there is still a need for patient-friendly yet efficient colon cleansing devices and methods that overcome the limitations of the prior art devices and methods. In particular, there is a need for an easy yet efficient method for washing a colon in the direction from the cecum towards the anus.
Delivery of a contrast agent, such as barium sulfate, into the colon is well known. Also known is combined delivery of gas and contrast agent, see U.S. Pat. No. 5,322,070. However, control over which specific portion of the colon is filled with barium remains limited. Furthermore, at present, in case of combined delivery of both barium and gas into the colon, one problem is how to control the properties of the barium coating of the colon wall, when the colon is filled with gas.
Conventional endoscopy uses cameras for imaging, often by way of taking two-dimensional pictures. Three-dimensional imaging in endoscopy is also known. See, for example, U.S. Pat. Nos. 6,503,195, 6,798,570, 6,949,069, 6,749,346, 6,563,105, 5,751,341, 5,673,147. A need exists for delivery of a camera into a lumen of a patient using a simple and self-guided technique. Also, after delivery, a need exists for providing images of the lumen in a simple and informative way.